System and method for introducing a substrate into a process chamber

ABSTRACT

A system and method for introducing a substrate into a process chamber is provided. A presence or absence of a substrate on a stage in an apparatus for manufacturing a semiconductor or a flat panel display may be determined by lift pins used for loading and unloading a substrate, the introduction of another substrate may be prevented and a broken state or the erroneously loaded state of the substrate may be detected. An opening or closing of a gate valve may also be determined, and the introduction of a substrate into the process chamber may be prevented while the gate valve is closed.

This application is a Divisional application of prior U.S. patentapplication Ser. No. 11/874,349 filed Oct. 18, 2007 now U.S. Pat. No.7,750,818, which claims priority under 35 U.S.C. §119 to Korean PatentApplication Nos. 10-2006-0118921 filed on Nov. 29, 2006; 10-2006-0118922filed Nov. 29, 2006; and 10-2006-0118924 filed Nov. 29, 2006, whoseentire disclosures are hereby incorporated by reference.

BACKGROUND

1. Field

This relates to substrate processing systems, and more particularly, tomonitoring systems used in substrate processing systems to facilitatethe transfer of substrates.

2. Background

Flat panel displays may include liquid crystal displays, plasma displaypanels, organic light emitting diodes, and other such devices. Theseflat panel displays may be manufactured using a vacuum processingapparatus that includes a process chamber, a load lock chamber and atransfer chamber.

The process chamber processes the surface of a substrate by, forexample, conducting an etching process using plasma, thermal energy, andthe like in a vacuum. The load lock chamber receives an unprocessedsubstrate from the outside, and discharges a processed substrate to theoutside while alternating between an atmospheric condition and a vacuumcondition. The transfer chamber may serve as an intermediate holdingplace when introducing and discharging substrates into and out of theprocess chamber. To this end, the transfer chamber may be positionedbetween the process chamber and the load lock chamber. Proper sequencingand transfer of substrates into and out of the process chamber isimportant in ensuring proper processing of the substrates and preventingdamage to the substrates during transfer.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments will be described in detail with reference to thefollowing drawings in which like reference numerals refer to likeelements wherein:

FIGS. 1A and 1B are cross-sectional views of an exemplary processchamber, wherein FIG. 1A illustrates a raised state of lift pins andFIG. 1B illustrates a lowered state of the lift pins;

FIGS. 2A and 2B are plan views of substrates positioned in the exemplaryprocess chamber shown in FIGS. 1A and 1B, wherein FIG. 2A illustrates abroken state of a substrate and FIG. 2B illustrates an erroneouslyloaded state of a substrate;

FIG. 3 is a plan view of an exemplary apparatus for manufacturing a flatpanel display;

FIG. 4 is a cross-sectional view of a process chamber to which a devicefor determining the presence or the absence of a substrate using liftpins, in accordance with a first embodiment as broadly described herein,may be applied;

FIG. 5 is an enlarged view of part ‘A’ of FIG. 4;

FIG. 6 is a partial cross-sectional view of a device for determining thepresence or the absence of a substrate using lift pins, in accordancewith a second embodiment as broadly described herein;

FIG. 7 is a partial cross-sectional view of a device for determining thepresence or the absence of a substrate using lift pins, in accordancewith a third embodiment as broadly described herein;

FIG. 8 is a flow chart of a method for introducing a substrate andinspecting a state of the introduced substrate by employing a device fordetermining the presence or the absence of a substrate using lift pins,in accordance with an embodiment as broadly described herein;

FIG. 9 is a cross-sectional view of a process chamber to which a devicefor determining the presence or the absence of a substrate using liftpins, in accordance with a fourth embodiment as broadly describedherein, may be applied;

FIGS. 10A and 10B are enlarged views of part ‘B’ of FIG. 9, wherein FIG.10A illustrates a state in which displacement does not occur in a liftpin and FIG. 10B illustrates a state in which displacement does occur.in the lift pin;

FIG. 11 is a cross-sectional view of a device for determining thepresence or the absence of a substrate using lift pins, in accordancewith a fifth embodiment as broadly described herein;

FIGS. 12A-12D are cross-sectional views of exemplary displacementsensing means which may be applied to the device for determining thepresence or the absence of a substrate using lift pins shown in FIG. 9;

FIGS. 13A-13D are cross-sectional views of various displacement sensingmeans which may be applied to the device for determining the presence orthe absence of a substrate using lift pins shown in FIG. 11;

FIG. 14 is a flow chart of a method for introducing a substrate andinspecting a state of the introduced substrate by employing the devicefor determining the presence or the absence of a substrate using liftpins shown in FIG. 9 or FIG. 11;

FIG. 15 is a cross-sectional view of an apparatus for manufacturing aflat panel display, to which a device for determining the opening or theclosing of a gate valve, in accordance with a sixth embodiment asbroadly described herein, may be applied;

FIG. 16 is an enlarged view of the gate valve sensing means shown inFIG. 15;

FIG. 17 is a cross-sectional view of the gate valve sensing means shownin FIG. 15, taken in the direction indicated by the arrow A′;

FIG. 18 is a partial cross-sectional view of a device for determiningthe opening or the closing of a gate valve, in accordance with a seventhembodiment as broadly described herein;

FIG. 19 is a partial sectional view of a device for determining theopening or the closing of a gate valve, in accordance with an eighthembodiment as broadly described herein;

FIG. 20 is a partial cross-sectional view of a device for determiningthe opening or the closing of a gate valve, in accordance with a ninthembodiment as broadly described herein; and

FIG. 21 is a perspective view of an exemplary transfer robot.

DETAILED DESCRIPTION

Reference will be made to various embodiments, examples of which areillustrated in the accompanying drawings. Wherever possible, the samereference numerals will be used throughout the drawings and thedescription to refer to the same or like parts.

FIGS. 1A and 1B are cross-sectional views of an exemplary processchamber. The process chamber may include a chamber 11 having a gate slit11 g in a sidewall thereof so that a substrate can be introduced into ordischarged from the chamber 11, an upper electrode assembly 12 installedin an upper region of the chamber 11, a lower electrode assembly 13positioned below the upper electrode assembly 12, a plurality of liftpins 14 installed in the lower electrode assembly 13, and a liftingmechanism 15 which simultaneously raises and lowers the plurality oflift pins 14. A gate slit and gate valve may also be provided with thetransfer chamber and/or the load lock chamber as appropriate.

The gate slit 11 g may be opened and closed by a gate valve 11 v. Asubstrate to be processed may be positioned on an upper surface of thelower electrode assembly 13, or “stage”. The lifting mechanism 15 mayinclude a pin plate 16 to which the lower ends of the respective liftpins 14 are fixed, and a ball screw 17 and a motor 18 which raise andlower the pin plate 16 in a ball screw driving manner.

To introduce a substrate into the process chamber a transfer robot (notshown), which is in a standby state in the load lock chamber (notshown), may be actuated. The substrate may be held above the lowerelectrode assembly 13 (hereinafter, referred to as a “stage”), as shownin FIG. 1A, and the lift pins 14 may be raised by the lifting mechanism15. Then, when the lift pins 14 are sufficiently raised, the transferrobot may place the substrate on the raised lift pins 14 and move out ofthe chamber 11, and the lift pins 14 may be lowered. As shown in FIG.1B, once fully lowered, the lift pins 14 are completely inserted intothe stage 13 and do not project above the upper surface of the stage 13,and the substrate is supported by the stage 13.

When the surface treatment of the substrate is completed, the lift pins14 may be raised to raise the substrate from the stage 13, and the armof the transfer robot may move into position below the substrate.Thereafter, as the lift pins 14 are lowered, the substrate may rest onthe arm of the transfer robot as the transfer robot moves out of thechamber 11 to discharge the substrate from the chamber 11. In theprocess chamber as described above, continuous introduction ofsubstrates is likely to continue unless the process is manuallyinterrupted. Thus, if a substrate is introduced into the chamber 11 forprocessing and another substrate is already positioned the chamber 11,the arm of the transfer robot and the previously introduced substratemay interfere with each other, possibly damaging one or both of thesubstrates.

To alleviate this problem, the chamber 11 may include an inspectionwindow (not shown) to allow the inside of the chamber 11 to be viewedfrom the outside. However, the inside of the chamber 11 may be poorlylit, or unlit, and thus it may be difficult to positively confirm thepresence of a substrate in the chamber 11. Further, performing a visualinspection of the inside of the chamber 11 every time a new substrate isto be introduced into the chamber 11 to check for the presence of asubstrate is time consuming and may slow down the manufacturing process.

If no visual inspection is conducted, or the inspection is inaccurate, asubstrate may be introduced into the chamber 11 in a broken state, asshown in FIG. 2A, or the introduced substrate may be erroneously loaded,as shown in FIG. 2B, depending upon the state of the transfer robot. Ifa broken or misaligned substrate is introduced into the chamber 11,processing operations may be performed on a substrate which mayultimately be rejected.

FIG. 3 is a plan view of an exemplary apparatus for manufacturing a flatpanel display which may include a load lock chamber 1, a process chamber2 having a gate slit 22 and a gate valve 24, a transfer chamber 3, atransfer robot 4, and a guide 5. The transfer robot 4 may include arobot body 42 which is moved along the guide 5 by a driving forcegenerated by driving means, and hands 44 provided with the robot body 42to receive substrates to be transferred.

To introduce a substrate into the process chamber 2 for processing, thegate valve 24 may be opened to open the gate slit 22. The transfer robot4 may be loaded with a substrate in the load lock chamber 1 and movedtoward the process chamber 2 along the guide 5, and may enter theprocess chamber 2 through the gate slit 22. Then, the transfer robot 4may unload the substrate and return to the transfer chamber 3. Duringprocessing, the gate valve 24 and gate slit 22 may remain closed.

As described above, when introducing the substrate into the processchamber 2, the gate valve 24 is necessarily opened to open the gate slit22. However, if the gate valve 24 remains closed due to, for example,breakdown or misoperation, this condition may not be recognized due tothe construction of the apparatus and the inspection capabilities as setforth above. Therefore, a substrate being transferred into the processchamber 2 by the transfer robot 4 may collide against the gate valve 24,possibly damaging the substrate, the transfer robot 4 and/or the gatevalve 24.

To address these issues, a process chamber, as shown in FIGS. 4 and 5,may include a chamber 51 which may provide a vacuum space for thesurface treatment of a substrate, an upper electrode assembly 52 and alower electrode assembly 53 which may be respectively installed facingeach other in an upper region and a lower region inside the chamber 51,a plurality of lift pins 54 which may be vertically raised and loweredthrough the lower electrode assembly 53, a pin lifting mechanism 55which may simultaneously raise and simultaneously lower the plurality oflift pins 54, and a device 60 which uses the lift pins 54 and associatedpin lifting mechanism 55 to determine whether a substrate is alreadypresent in the chamber 51. The chamber 51 may have a gate slit 51 g inone sidewall thereof through which a substrate may be introduced into ordischarged from the chamber 51. The gate slit 51 g may be opened andclosed by a gate valve 51 v. A bellows 59 may enclose the lift pins 54between the chamber 51 and a portion of the pin lifting mechanism 55 tomaintain a vacuum state in the chamber 51.

The upper electrode assembly 52 may include a shower head (not shown)for injecting a processing gas for surface treatment of the substrate.The lower electrode assembly 53 may serve as a chuck top on which theintroduced substrate may be placed, and thus a receiving surface of thelower electrode assembly 53 may be referred to as a “stage”. The lowerelectrode assembly 53 may include pin holes 53 h through which therespective lift pins 54 may be raised and lowered. The pin holes 53 hmay extend in the vertical direction, or in a direction that correspondsto an orientation of the lift pins 54. The pin holes 53 h may beprovided at regular intervals adjacent to the edges of the lowerelectrode assembly 53 (hereinafter, referred to as the “stage”). Thenumber and the positions of the pin holes 53 h may be changed dependingupon the number and the locations of the lift pins 54 and thepositioning, support and movement required by the substrate.

The pin lifting mechanism 55 may include a pin plate 56 to which thelower ends of the respective lift pins 54 may be fixed, and drivingmeans for raising and lowering the pin plate 56. The driving means shownin FIG. 4 includes a ball screw 57 coupled to the pin plate 56, and amotor 58 for rotating the ball screw 57 in two directions (clockwise andcounter-clockwise). Other components for the driving means may also beappropriate.

The device 60 for determining the presence or the absence of a substratemay include substrate sensing means 61, determination means 62 andnotification means 63. The substrate sensing means 61 may sense whetherthe load of a substrate acts on the lift pins 54 when the lift pins 54are raised to project from the stage 53 and support the substrate. Thesubstrate sensing means 61 may be configured in a manner such that, whenit is sensed that the load of the substrate acts on the lift pins 54,corresponding sensing results, or sensing signals, are output from thesubstrate sensing means 61 to the determination means 62. To facilitatethe substantially immediate output of such a signal, the determinationmeans 62 may be electrically connected to the substrate sensing means61.

The substrate sensing means 61 may include sensors installed on therespective upper ends of some or all of the lift pins 54 to be broughtinto contact with the substrate, and to be actuated by the load of thesubstrate when the load of the substrate acts on the lift pins 54. Whenthe sensors receive the load of the substrate, the sensors may beactuated by the load of the substrate and output corresponding sensingsignals to the determination means 62. For example, a push switch may beconfigured such that an electrical connection is mechanically generatedwhen the push switch is pushed. Alternatively, an electric contactsensor or an electric strain gauge that electrically senses contact withthe substrate may be employed.

The determination means 62 may receive sensing signals from thesubstrate sensing means 61, that is, the sensors, and thereby determinethe presence or the absence of a substrate. The determination means 62may include control means for controlling the operation of an apparatusfor manufacturing a flat panel display. When it is determined asdescribed above that a substrate is present in the chamber 51, thecontrol means may output a corresponding control signal such that thenotification means 63, which may be electrically connected to thecontrol means, may be actuated. Conversely, if it is determined that nosubstrate is present in the chamber 51, the control means may output acorresponding control signal such that a substrate to be processed maybe introduced into the chamber 51. In this way, the control means maycontrol operation of the apparatus for manufacturing a flat paneldisplay.

The notification means 63 may notify a worker of the presence of asubstrate under control of the control means. The notification means 63may include, for example, a warning lamp 63 w or monitor for visualnotification, a speaker 63 s or buzzer, for auditory notification, orother means as appropriate. Likewise, visual notification means andauditory notification means may be used together.

Warning lamps 63 w may be provided in a number that corresponds to thenumber of sensors 61 (the number of lift pins 54 if each lift pin 54 hasa sensor 61) so that, when each sensor 61 outputs a sensing signal, thecontrol means may turn on the corresponding warning lamp 63 w inresponse to the sensing signal. In this scenario, due to the fact thatthe sensors 61 are installed on each of the respective lift pins 54, ifthe load of the substrate in the chamber 51 is not evenly distributedand thus does not act on all the lift pins 54, it may be determined thatthe substrate is partially broken or has been erroneously loaded if theload of the substrate does not act on all of the lift pins 54. As aconsequence, it may be possible to determine whether the introducedsubstrate is in an appropriate state.

As shown in FIG. 6, a device for determining the presence or the absenceof a substrate using lift pins in accordance with a second embodimentmay include substrate sensing means 61A respectively mounted to thelower ends of the lift pins 54 so as to be positioned between the liftpins 54 and a support structure thereof, such as, for example, the pinplate 56. Alternatively, the support structure may include othercomponent elements as long as they are positioned along the lines ofaction along which the load of the substrate acts on the lift pins 54,to support the lift pins 54.

As shown in FIG. 7, in a device for determining the presence or theabsence of a substrate using lift pins according to a third embodiment,each lift pin 54B may include an upper pin 54 u positioned at an upperposition, and a lower pin 54 d positioned below the upper pin 54 u.Therefore, when viewed in its entirety, each lift pin 54B may have astructure which is divided into upper and lower parts. Substrate sensingmeans 61B may be positioned between the upper pin 54 u and the lower pin54 d of the lift pin 54B divided in this manner. The substrate sensingmeans 61B may be mounted to the upper end of the lower pin 54 d, or tothe lower end of the upper pin 54 u.

A method for introducing a substrate and inspecting a state of theintroduced substrate using any one of the devices for determining thepresence or the absence of a substrate according to the first throughthird embodiments will now be described with reference to FIG. 8.

During normal operation, the lift pins 54 may be lowered and insertedinto the pin holes 53 h such that the upper ends thereof do not projectfrom the stage 53. To introduce into the chamber 51 a substrate which isin a standby state in a load lock chamber, and load the substrate ontothe stage 53 for processing, the plurality of lift pins 54 may besimultaneously raised to receive the substrate and then lowered tooriginal positions thereof by the driving force from the pin liftingmechanism 55 (S1).

The sensors of the substrate sensing means 61 sense whether a substrateis placed on the lift pins 54 by sensing whether the load of thesubstrate acts on the lift pins 54 and transmits the sensing results tothe control means (S2). The control means determines that a substrate ispresent if a sensing signal from at least one sensor is inputted thereto(S3). Conversely, if no sensing signal is inputted from the sensors, thecontrol means determines that no substrate is present (S4).

When the presence of a substrate is determined (S3), the control meansoutputs a control signal and actuates the notification means 63 (S13). Aworker may recognize the presence of the substrate based on thenotification, and may take subsequent necessary actions. In this case,the control means may be further configured to prevent the introductionof a new substrate if an existing substrate is sensed in the chamber 51.Alternatively, or alternately, the process may proceed to determiningwhether or not a load acts on all of the lift pins 54 (S&) to determinea state of the detected substrate.

When the absence of a substrate is determined (S4), the transfer robotmay be driven to introduce a substrate to be processed, and position thesubstrate above the stage 53 (S5). The lift pins 54 may be raised toreceive the newly introduced substrate from the transfer robot, and thenlowered to the original positions (S6). After the lift pins 54 receivethe substrate, the transfer robot may move out of the chamber 51.

The sensors sense whether the load of the substrate acts on all of thelift pins 54, and the control means receives the sensing results fromthe sensors (S7). If a sensing signal is not received from each of thesensors, the control means determines that a corresponding portion ofthe substrate is broken (see FIG. 2A) or that the substrate has beenerroneously loaded (see FIG. 2B) (S8). Conversely, if sensing signalsare inputted from all the sensors, the control means determines that thesubstrate is not broken and that the substrate has been correctly loaded(S9).

If it is determined that the substrate is in an inappropriate state(S8), the control means outputs a signal to actuate the notificationmeans 63 (S13) in order to notify the worker of this situation.Therefore, the worker can recognize the state of the substrate and cantake appropriate action. The control means may be further configured tointerrupt the implementation of a following process until the worker hastaken corrective action.

Conversely, if it is determined that the substrate is in an appropriatestate (S9), the surface treatment of the substrate is implemented (S10).If the surface treatment is completed, the substrate, having completelyundergone the surface treatment, is discharged through raising of thelift pins 54, introduction of the transfer robot into the chamber 51,lowering of the lift pins 54, and movement of the transfer robot out ofthe chamber 51 (S11). The apparatus may then either process anothersubstrate, or complete processing (S12).

A process chamber and a device for determining the presence or theabsence of a substrate using lift pins in accordance with a fourthembodiment as shown in FIGS. 9 and 10A-10B may include a chamber 151, agate slit 151 g, a gate valve 151 v, an upper electrode assembly 152, astage 153, pin holes 153 h, a plurality of lift pins 154A, a pin liftingmechanism 155, a pin plate 156, a ball screw 157, a motor 158, bellows159, and a device 160 for determining the presence or the absence of asubstrate. Among these component elements, the chamber 151, the gateslit 151 g, the gate valve 151 v, the upper electrode assembly 152, thestage 153, the pin holes 153 h, the pin lifting mechanism 155, the pinplate 156, the ball screw 157, the motor 158, and the bellows 159 aresimilar to those discussed previously, and therefore, detaileddescriptions thereof will be omitted herein.

The plurality of lift pins 154A may have a structure in which, dependingupon whether or not a substrate is placed on the stage 153, a projectingheight of the lift pins 154A is changed and the lift pins 154A aredisplaced. Each lift pin 154A may include a body and an elastic memberE1 that elastically supports the body. In certain embodiments, eachelastic member E1 may be a coil spring installed at the lower end of thebody of the lift pin 154A, positioned between the body of the lift pin154A and the pin plate 156. The coil spring may also provide a supportstructure for supporting the lift pin 154A.

If the pin lifting mechanism 155 is actuated with a substrate placed onthe stage 153 and each lift pin 154A is raised, the elastic member E1 iscompressed by the load of the substrate, as shown in FIG. 10B, and theprojecting height of the lift pin 154A is decreased in comparison towhen the lift pin 154A is raised with no substrate placed on the stage153, as shown in FIG. 10A. The elastic member E1 may have a strengthsuch that it is compressed by the load of the substrate, but is notcompressed by the load of the body of the lift pin 154A when nosubstrate is placed on the stage 153. The elastic member E1 may be acoil spring, as shown, rubber, sponge, or other suitable component.

The displacement structure of the lift pin 154A is shown in FIGS. 10Aand 10B. In FIG. 10A, the lift pin 154A is raised with no substrateplaced on the stage 153, and H1 represents the corresponding projectingheight of the lift pin 154A. In FIG. 10B, the lift pin 154A is raisedwith a substrate placed on the stage 153, and H2 represents thecorresponding projecting height of the lift pin 154A.

The device 160 for determining the presence or the absence of asubstrate, as shown in FIG. 9, may include displacement sensing means161A, determination means 164 and notification means 165.

Each displacement sensing means 161A senses whether the elastic memberE1 is compressed by a substrate to change the projecting height of thelift pin 154A from a completely raised position in which the lift pin154A projects from the stage 153 by a predetermined height. When it issensed that the lift pin 154A is displaced, the corresponding sensingresult (the corresponding sensing signal) is transmitted from thedisplacement sensing means 161A to the determination means 164. Toprovide for substantially immediate transmission of this signal, thedetermination means 164 may be electrically connected to thedisplacement sensing means 161A.

The displacement sensing means 161A sense the displacements of all therespective lift pins 154A. The displacement sensing means 161A may berespectively installed along the lines of action, along which force forcompressing the elastic members E1 acts, so as to be actuated by theforce when the elastic members E1 are compressed and the intervalsbetween the bodies of the lift pins 154A and the pin plate 156 aredecreased. The displacement sensing means 161A may include sensors in amanner such that, when the sensors receive the force, the sensors areactuated by the force and output sensing signals to the determinationmeans 164.

In certain embodiments, each sensor may be installed on the pin plate156 and inserted into the coil spring that forms the elastic member E1so as to be positioned between the body of the lift pin 154A and the pinplate 156. Other installation arrangements may also be appropriate, andit is sufficient for each sensor to be positioned along the line ofaction so that each sensor can receive the action force. For example, anactuation aim may be provided at a lower portion of the body of the liftpin 154A to extend perpendicularly to the direction in which the liftpin 154A is raised and lowered, and a sensor may be installed on the pinplate 156 to be positioned between the actuation arm and the pin plate156.

The sensors described above may be, for example, a push switchconfigured such that an electrical connection may be mechanically formedwhen the push switch is pushed (by the body of the lift pin 154A).Alternatively, an electric contact sensor or an electric strain gaugethat electrically senses contact between the substrate and the body ofthe lift pin 154A may be used.

The determination means 164 receives sensing signals from thedisplacement sensing means 161A, that is, the sensors, and determinesthe presence or the absence of a substrate. The determination means 164may include control means for controlling the operation of an apparatusfor manufacturing a flat panel display.

When it is determined that a substrate is present in the chamber 151,the control means may output a corresponding control signal such thatthe notification means 165, which may be electrically connected to thecontrol means, may be actuated. Conversely, if it is determined that nosubstrate is present in the chamber 151, the control means may output acorresponding control signal such that a substrate to be processed maybe introduced into the chamber 151. In this way, the control meanscontrols the operation of the apparatus for manufacturing a flat paneldisplay.

The notification means 165 may notify a worker of the presence of asubstrate under the control of the control means. The notification means165 may be, for example, a warning lamp 165 w or a monitor for visualnotification, or a speaker 165 s or a buzzer for auditory notification.Other components may also be appropriate, and the visual notificationmeans and auditory notification means may be used together.

Notification of the presence of a substrate may be implemented in anumber of warning lamps 165 w which corresponds to a number of sensors(that is, a number of lift pins 154A). Thus, when any one sensor outputsa sensing signal, the control means may turn on the correspondingwarning lamp 165 w in response to the sensing signal. If displacementdoes not occur in all the lift pins 154A (and one or more of the warninglamps 165W is not lit), even though a substrate is positioned thechamber 151, it can be determined that the substrate may be partiallybroken and/or erroneously loaded because the load of the substrate isnot acting on one or more of the lift pins 154A. Consequently, it ispossible to determine whether the substrate in the chamber 151 is in anappropriate state.

A device for determining the presence or the absence of a substrateusing lift pins in accordance with a fifth embodiment as shown in FIG.11 may include a plurality of lift pins 154B each having an upper pin154 u, a lower pin 154 d positioned below the upper pin 154 u and fixedto the pin plate 156 at the lower end thereof, and an elastic member E2installed on the upper pin 154 u or the lower pin 154 d so as to bepositioned between the lower pin 154 d and the upper pin 154 u and toelastically support the upper pin 154 u.

The elastic member E2 may be a coil spring, rubber, sponge, or othersuitable elastic component. In the same manner as the elastic member E1shown in FIGS. 9-10B, the elastic member E2 may have sufficient strengthto be compressed by the load of the substrate, but not to be compressedby the load of the upper pin 154 u.

When comparing the projecting heights H2 of the lift pin 154B in a statein which a substrate is placed on the stage 153 to a projecting heightH1 in which a substrate is not placed on the stage 153, in the case ofthe lower pin 154 d, the projecting height is not changed, whereas, inthe case of the upper pin 154 u, the projecting height is changed anddisplacement occurs.

The displacement sensing means 161B may perform functions similar tothose of the displacement sensing means 161A shown in FIGS. 9-10B. Eachdisplacement sensing means 161B may be installed on the upper pin 154 uor the lower pin 154 d, with an appropriate end inserted into the coilspring elastic member E2 so as to be positioned between the upper pin154 u and the lower pin 154 d.

In alternative embodiments, the lift pin 154B may be constructed in sucha way that the point at which the lift pin 154B is divided into theupper pin 154 u and the lower pin 154 d is always positioned outside ofthe chamber 151. When so configured, when the lift pin 154B is in theraised state, by providing an actuation arm (not shown) on the lower pin154 d as described above, the displacement sensing means 161B mayinstead be installed between the actuation arm and the pin plate 156.

Various embodiments of displacement sensing means for use with thefourth embodiment as broadly described herein are shown in FIGS.12A-12D. As shown in FIG. 12A, each displacement sensing means 162A mayinclude a light emitting sensor F1 and a light receiving sensor R1. Oneof the light emitting sensor F1 or the light receiving sensor R1 may beinstalled on the body of the lift pin 154A, and the other may beinstalled on the wall of the pin hole 153 h. The light receiving sensorR1 receives a signal from the light emitting sensor F1. To this end, thelight emitting sensor F1 and the light receiving sensor R1 may bepositioned opposite each other when the lift pin 154A is raised. If thelight emitting sensor F1 and the light receiving sensor R1 are installedin this way, the light emitting sensor F1 and the light receiving sensorR1 can output and receive signals as the lift pin 154A is raised,irrespective of the presence of the substrate. For this reason, theoutput and receipt of a signal by the light emitting sensor F1 and thelight receiving sensor R1, respectively, may be permitted only when thelift pin 154A is raised. Alternatively, the corresponding determinationmay be made only when the control means has received a signal from thedisplacement sensing means 162A for at least a predetermined time.

As shown in FIG. 12B, either one of the light emitting sensor F1 and thelight receiving sensor R1 may instead be positioned at a predeterminedheight above the pin plate 156, rather than on the wall of the pin hole153 h. A bracket BR may be provided for holding the light emittingsensor F1 or the light receiving sensor R1 at the predetermined heightfrom the pin plate 156.

As shown in FIG. 12C, the light emitting sensor F1 and light receivingsensor R1 may instead be located in opposite side walls of the pin hole153 h, with the lift pin 154A interposed therebetween. A signaltransmission hole T1 may extend through the lift pin 154A such that thelight emitting sensor F1 and the light receiving sensor R1 may exchangea signal when aligned with the transmission hole T1. Thus, when the liftpin 154A is raised, the signal output by the light emitting sensor F1may pass through the signal transmission hole T1 and be received by thelight receiving sensor R1.

As shown in FIG. 12D, the displacement sensing means 163A may include alight emitting sensor F1, a light receiving sensor R1 and a reflectionplate P1. The light emitting sensor F1 may output a signal to thereflection plate P1, and the light receiving sensor R1 may receive thesignal reflected by the reflection plate P1. The reflection plate P1 maybe installed on the lift pin 154A and both the light emitting sensor F1and the light receiving sensor R1 may be installed on the wall of thepin hole 153 h. The light emitting sensor F1 may be located such that asignal is transmitted toward the reflection plate P1 when displacementoccurs in the lift pin 154A, and the light receiving sensor R1 may belocated such that the signal transmitted by the light emitting sensor F1and reflected by the reflection plate P1 may be received by the lightreceiving sensor R1 when displacement occurs in the lift pin 154A.

Various embodiments of displacement sensing means for use with the fifthembodiment as broadly described herein are shown in FIGS. 13A-13D. Theseembodiments may include a light emitting sensor F2, a light receivingsensor R2 and a reflection plate P2 similar to those discussed abovewith respect to FIGS. 12A-12D.

As shown in FIG. 13A, each displacement sensing means 162B may include alight emitting sensor F2 and a light receiving sensor R2. One of thelight emitting sensor F2 or the light receiving sensor R2 may beinstalled on the upper pin 154 u of the lift pin 154B, and the other maybe installed on the wall of the pin hole 153 h such that the lightemitting sensor F2 and the light receiving sensor R2 are positionedopposite each other when the lift pin 154B is raised.

As shown in FIG. 13B, one of the above-described light emitting sensorF2 or the light receiving sensor R2 may instead be held by a bracket BRat a predetermined height from the pin plate 156, rather than on thewall of the pin hole 153 h.

As shown in FIG. 12C, the above-described light emitting sensor F2 andlight receiving sensor R2 may instead be located on opposite side wallsof the pin hole 153 h, with the lift pin 154B interposed therebetween. Asignal transmission hole T2 may extend through the upper pin 154 u suchthat the light emitting sensor F2 and the light receiving sensor R2 mayexchange a signal when the lift pin 154B is raised and the signaltransmission hole T1 is aligned therewith.

As shown in FIG. 13D, the displacement sensing means 163B may include alight emitting sensor F2, a light receiving sensor R2 and a reflectionplate P2. The reflection plate P2 may be installed on the upper pin 154u, and both the light emitting sensor F2 and the light receiving sensorR2 may be installed on the wall of the pin hole 153 h. The lightemitting sensor F2 may be located such that a signal is transmittedtoward the reflection plate P2 when displacement occurs in the lift pin154B, and the light receiving sensor R2 may be located such that thesignal reflected by the reflection plate P2 may be received by the lightreceiving sensor R2 when displacement occurs in the lift pin 154B.

A method for introducing a substrate and inspecting the state of theintroduced substrate using the device for determining the presence orthe absence of a substrate according to the fourth embodiment or thefifth embodiment as broadly described herein will be described withreference to FIG. 14.

For reference, the device for determining the presence or the absence ofa substrate according to the fourth embodiment (which includes severalvariations of the displacement sensing means) and the device fordetermining the presence or the absence of a substrate according to thefifth embodiment (which also includes several variations of thedisplacement sensing means) may be similarly used in the method forintroducing a substrate and inspecting the state of the introducedsubstrate shown in FIG. 8. Simply for ease of discussion, this methodwill be described using the device for determining the presence or theabsence of a substrate according to the fourth embodiment. However, itis well understood that this method may also be applied with the fifthembodiment.

During normal operation, the lift pins 154A may be lowered and insertedinto the pin holes 153 h such that the upper ends thereof do not projectfrom the stage 153. To introduce into the chamber 151 a substrate whichis in a standby state in a load lock chamber, and load the substrateonto the stage 153 for processing, the plurality of lift pins 154A maybe simultaneously raised to receive the substrate, and then lowered tooriginal positions thereof, by the driving force from the pin liftingmechanism 155 (S101).

In this procedure, the sensors of the displacement sensing means 161Amay sense whether a substrate is placed on the lift pins 154A and theelastic members E1 are compressed by the load of the substrate to causedisplacement of the lift pins 154A when the lift pins 154A are raised,and the control means may receive the sensing results from the sensors(S102). The control means may determine the presence of a substrate if asensing signal from at least one sensor is inputted thereto (S103).Conversely, if no sensing signal is inputted from the sensors, thecontrol means determines the absence of a substrate (S104).

When the presence of a substrate is determined (S103), the control meansoutputs a control signal and actuates the notification means 165 (S113).A worker can recognize the presence of the substrate based on thenotification, and may take necessary actions. In this case, the controlmeans may be further configured to prevent the introduction of a newsubstrate if an existing substrate is sensed in the chamber 151.Alternatively, or additionally, the process may proceed to determiningwhether or not displacement occurs in each of the lift pins 154A (S107)to determine a state of the detected substrate.

When the absence of a substrate is determined (S104), the transfer robotmay be driven to introduce a substrate to be processed, and position thesubstrate above the stage 153 (S105). The lift pins 154A may be raisedto receive thereon the newly introduced substrate from the transferrobot, and then lowered to their original positions (S106). After thelift pins 154A receive the substrate, the transfer robot may move out ofthe chamber 151.

The sensors sense whether displacement occurs in the lift pins 154A, andthe control means receives the sensing results from the sensors (S107).If a sensing signal is not received from each of the sensors, thecontrol means determines that the corresponding portion of the substrateis broken (see FIG. 2A) and/or that the substrate has been erroneouslyloaded (see FIG. 2B) (S108). Conversely, if sensing signals are receivedfrom all the sensors, the control means determines that the substrate isnot broken and that the loading of the substrate has been appropriatelyimplemented (S109).

If it is determined that the substrate is in an inappropriate state(S108), the control means outputs a signal to actuate the notificationmeans 165 (S13), in order to notify the worker of this situation.Therefore, the worker can recognize the state of the substrate and cantake appropriate corrective actions. The control means may be furtherconfigured to interrupt subsequent processing until corrective actionhas been implemented.

Conversely, if it is determined that the substrate is in an appropriatestate (S109), the surface treatment of the substrate is implemented(S110). If the surface treatment is completed, the substrate, havingcompletely undergone the surface treatment, is discharged throughraising of the lift pins 154A, introduction of the transfer robot intothe chamber 151, lowering of the lift pins 154A and movement of thetransfer robot out of the chamber 151 (S111). The apparatus may theneither process another substrate, or complete the processing operation(S112).

FIG. 15 is a cross-sectional view of an apparatus for manufacturing aflat panel display to which a device for determining the opening or theclosing of a gate valve, in accordance with a sixth embodiment asbroadly described herein, may be applied.

The apparatus may include a load lock chamber 260 which receives anunprocessed substrate from the outside and stores it, or receives aprocessed substrate and discharges it to the outside. The apparatus mayalso include a process chamber 270 which receives the unprocessedsubstrate from the load lock chamber 260 and processes it, and which hasdefined in a sidewall thereof a gate slit 272 opened and closed by agate valve 274 serving as a gateway for a substrate. The apparatus mayalso include a transfer chamber 280 provided between the process chamber270 and the load lock chamber 260, a transfer robot 290 provided in thetransfer chamber 280 to reciprocate between the load lock chamber 260and the process chamber 270 and transfer a substrate from the load lockchamber 260 to the process chamber 270 or from the process chamber 270to the load lock chamber 260, a guide G-1 which guides the precisemovement of the transfer robot 290, and a device 300 which determinesthe opening or the closing of the gate valve 274.

The load lock chamber 260 and the transfer chamber 280 may be connectedby a transfer passage P-1, and the process chamber 270 and the transferchamber 280 may be connected by a transfer passage P-2. A gateway for asubstrate may be defined between the load lock chamber 260 and thetransfer chamber 280 to serve in a similar manner as the gate slit 272,and a door (a gate valve) may be installed in the gateway to open andclose the gateway.

The process chamber 270 may be configured to implement surface treatmentof a substrate under a vacuum condition. The treatment may beimplemented using plasma, thermal energy, and the like. Also, the gatevalve 274 of the process chamber 270 may open and close the gate slit272 outside the process chamber 270. The gate valve 274 may be a rotarytype, in which one end thereof is hingedly coupled to the processchamber 270 to open and close the gate slit 272 as it pivots, or as avertical movement type, in which the gate valve 274 moves linearly toopen and close the gate slit 272. The gate valve 274 may be actuated bydriving means (not shown).

The transfer robot 290 may include a robot body 292 which moves on theguide G-1, hands 294 connected to the robot body 292 and on whichsubstrates to be transferred are respectively placed, and driving means(not shown) which provides driving force for moving the robot body 292.

The device 300 which determines the opening or the closing of the gatevalve 274 may include gate valve sensing means 310A, determination means320 and notification means 330. The gate valve sensing means 310A maysense whether the gate valve 274 is opened to open the gate slit 272 oris closed to close the gate slit 272. The gate valve sensing means 310Amay be configured such that, when the closing of the gate valve 274 issensed, the corresponding sensing result (a sensing signal) may besubstantially immediately output from the gate valve sensing means 310Ato the determination means 320, which electrically connected to the gatevalve sensing means 310A.

As shown in FIGS. 16 and 17, the gate valve sensing means 310A mayinclude a reflection plate 312 a and an optical sensor module. Thereflection plate 312 a may be installed on the outer side (the surfacefacing the transfer chamber 280) of the gate valve 274. The opticalsensor module may output a signal (light) to the reflection plate 312 aand receive the signal reflected by the reflection plate 312 a. Theoptical sensor module may include a light emitting sensor 314 a and alight receiving sensor 316 a.

The light emitting sensor 314 a outputs a signal to the reflection plate312 a, and the light receiving sensor 316 a receives the signal outputby the light emitting sensor 314 a and reflected by the reflection plate312 a. In order to make this possible, the optical sensor module may beplaced at a position opposite the reflection plate 312 a. Thus, theoptical sensor module may be installed on the guide G-1, which guidesthe movement of the transfer robot 290 as described above. The lightemitting sensor 314 a and the light receiving sensor 316 a may beinstalled so as not to interfere with the movement of the transfer robot290 on the guide G-1. The installation positions of the reflection plate312 a and the optical sensor module may be reversed, with the reflectionplate 312 a installed on the guide G-1, and the optical sensor moduleinstalled on the gate valve 274.

As described above, the determination means 320 receives the sensingresult from the gate valve sensing means 310A and determines whether thegate valve 274 is in an opened state or a closed state. Thedetermination means 320 may include control means for controlling theoperation of the apparatus for manufacturing a flat panel display.

When the control means receives a sensing result from the gate valvesensing means 310A indicating that the gate valve 274 is closed, thecontrol means outputs a corresponding control signal such that thenotification means 330, which may be electrically connected to thecontrol means, may be actuated. When the control means determines thatthe gate valve 274 is open, the control means outputs a correspondingcontrol signal such that a substrate that is being stored in the loadlock chamber 260 and has not been processed may be transferred by thetransfer robot 290 and introduced into the process chamber 270.

The notification means 330 may notify a worker whether the gate valve274 is opened or closed under control of the control means. Thenotification means 330 may include a warning lamp 332 (which, forexample, may be turned on to indicate the opening of the gate valve 274and turned off to indicate the closing of the gate valve 274, orvice-versa). Alternately, a monitor for visual notification may beadopted, or a speaker 334 (which, for example, may generate no sound toindicate the opening of the gate valve 274 and generate sound toindicate the closing of the gate valve 274, or vice-versa) or a buzzerfor auditory notification may be adopted. Additionally, visualnotification means and auditory notification means may be adoptedtogether.

A device for determining the opening or the closing of a gate valve, inaccordance with a seventh embodiment, as shown in FIG. 18, may includegate valve sensing means 310B including a light emitting sensor 314 binstalled outside the gate valve 274, and a light receiving sensor 316 binstalled on the guide G-1. The light emitting sensor 314 b may output asignal (light), and the light receiving sensor 316 b may receive thesignal output by the light emitting sensor 314 b. Thus, the lightemitting sensor 314 b and the light receiving sensor 316 b may beinstalled opposite one another, and their installation positions may bereversed.

A device for determining the opening or the closing of a gate valve, inaccordance with an eighth embodiment, as shown in FIG. 19, may includegate valve sensing means 310C including a light emitting sensor 314 cinstalled on the outer side of the gate valve 274, and a light receivingsensor 316 c provided on the transfer robot 290 and positioned oppositethe light emitting sensor 314 c. The light receiving sensor 316 c may beinstalled on a distal end of the hand 294 of the transfer robot 290. Theinstallation positions of the light emitting sensor 314 c and the lightreceiving sensor 316 c may be reversed, and light receiving sensor 316 cneed not be necessarily installed on the hand 294. It is sufficient forthe light receiving sensor 316 c to be installed on the transfer robot290 so as to be capable of exchanging a signal with the light emittingsensor 314 c and so as not to obstruct the operation of the transferrobot 290.

Although the device for determining the opening or the closing of a gatevalve in accordance with the eighth embodiment has been explained as avariation of the construction of the seventh embodiment, the eighthembodiment may also be explained by varying the construction of thesixth embodiment. In this case, one of the reflection plate or theoptical sensor module may be installed on the gate valve 274, and theother may be installed on the transfer robot 290.

A device for determining the opening or the closing of a gate valve, inaccordance with a ninth embodiment, as shown in FIG. 20, may includegate valve sensing means 310D including a sensor held by a bracket B-1.This sensor may be installed on a line of action along which the forcefor closing the gate valve 274 is applied, so as to be actuated by theforce. When the force is applied to the sensor, the sensor is actuatedthereby, and outputs a sensing signal to the determination means 320(see FIG. 15). The sensor may be installed over the gate valve 274 so asto come into contact with the upper surface of the gate valve 274 whenthe gate valve 274 is closed. The sensor need not be necessarilyinstalled in this way, and it is sufficient for the sensor to beinstalled so as to be positioned on the line of action and thereby besubjected to the action force. For example, a push switch may beconfigured such that an electrical connection is mechanically createdwhen the push switch is pushed by the gate valve 274. Alternatively, anelectric contact sensor or an electric strain gauge for electricallysensing contact with the gate valve 274 may be employed.

FIG. 21 is a perspective view of an exemplary transfer robot includingan arm provided between a robot body and robot hands. The arm may beconstructed to fold and unfold, as shown in shadow in FIG. 21. In thedevices for determining the opening or the closing of a gate valveaccording to the sixth through eighth embodiments, the componentelements of the gate valve sensing means may be installed on the robotbody, the hand or the arm of the transfer robot.

A method for introducing a substrate into a process chamber using thedevice for determining the opening or the closing of a gate valveaccording to embodiments as broadly described herein will be discussed.For reference, the device according to the sixth embodiment and thedevices according to the other embodiments may be similarly used in themethod for introducing a substrate. Hereafter, the method will bedescribed using the device according to the sixth embodiment.

During normal operation, the gate valve 274 is kept closed, and the gateslit 272 is maintained in the closed state. The device 300 fordetermining the opening or the closing of a gate valve determineswhether the gate valve 274 is opened or closed, and indicates this to aworker.

If the gate valve 274 is closed, the signal output by the light emittingsensor 314 a of the gate valve sensing means 310A is directed toward thereflection plate 312 a, which is installed on the gate valve 274. Thissignal is reflected by the reflection plate 312 a and is received by thelight receiving sensor 316 a. At this time, the gate valve sensing means310A outputs the corresponding sensing result to the determination means320. The determination means 320 receives the sensing result, determinesthat the gate valve 274 is closed, and outputs a corresponding controlsignal to the notification means 330. The notification means 330notifies a worker that the gate valve 274 is closed.

When it is necessary to introduce a substrate to be processed into theprocess chamber 270 and process the substrate, the gate valve 274 may beopened by, for example, being lowered by the driving force of thedriving means. If the gate valve 274 cannot be opened due to, forexample, breakdown or misoperation, the device 300 for determining theopening or the closing of a gate valve notifies the worker that the gatevalve 274 is still closed. The worker can then precisely recognize theopened or the closed state of the gate valve 274 and can take necessarycorrective action. In this case, the determination means 320 may befurther configured to prevent the introduction of a substrate untilcorrective action has been implemented.

As the gate valve 274 is opened, a position of the reflection plate 312a changes with respect to the opened gate valve 274, the reflectionplate 312 a cannot reflect the signal output the light emitting sensor314 a, and the light receiving sensor 316 a cannot receive the signalfrom the light emitting sensor 314 a. As a consequence, the device 300for determining the opening or the closing of a gate valve notifies theworker that the gate valve 274 is open.

When it is determined by the device 300 that the gate valve 274 is open,the transfer robot 290 conducts an introducing process, as describedbelow.

The transfer robot 290 is moved along the guide G-1 to the load lockchamber 260. In the load lock chamber 260, a substrate to be processedis loaded on the hand 294, and then the transfer robot 290 is movedalong the guide G-1 to the process chamber 270. The transfer robot 290enters the process chamber 270 through the gate slit 272, the substrateloaded on the hand 294 is unloaded in the process chamber 270, and thetransfer robot 290 is returned to its original position in the transferchamber 280. When the transfer robot 290 moves out of the processchamber 270, the gate valve 274 is closed by, for example, being raisedby the driving force of driving means, and processing of the substrateis conducted in the process chamber 270.

A device is provided that determines the presence or the absence of asubstrate using lift pins, in which whether the load of a substrate actson lift pins is sensed, and the presence or the absence of a substrateis determined depending upon the sensing result, so that a worker canquickly and conveniently confirm the presence of a substrate.

A device is provided that determines the presence or the absence of asubstrate using lift pins, in which the projecting height of the liftpins is changed depending upon the presence or the absence of asubstrate, whether displacement occurs in the lift pins is sensed, andthe presence or the absence of a substrate is determined depending uponthe sensing result, so that a worker can quickly and convenientlyconfirm the presence of a substrate.

A device that determines the presence or absence of a substrate asembodied and broadly described herein may include a plurality of liftpins installed to be raised and lowered through pin holes definedthrough a stage on which a substrate is placed, such that the lift pinsare raised when the substrate is introduced into a chamber; substratesensing means for sensing whether the raised lift pins carry thesubstrate; and determination means for receiving a sensing result fromthe substrate sensing means and determining the presence or absence ofthe substrate.

The substrate sensing means may sense whether the load of the substrateacts on the lift pins.

The substrate sensing means may include a sensor installed on at leastone of lines of action, along which the load of the substrate acts onthe lift pins, to be actuated by the load of the substrate.Alternatively, the substrate sensing means may include sensors installedalong respective lines of action, along which the load of the substrateacts on the lift pins, to be actuated by the load of the substrate.

The sensors may be installed on upper ends of the lift pins to bebrought into contact with the substrate, or may be installed between thelift pins and a lift pin support structure. Alternatively, each lift pinmay be divided into an upper pin and a lower pin, and each sensor can beinstalled between the upper pin and the lower pin.

The respective lift pins may have a structure in which the projectingheights thereof change depending upon whether the lift pins carry thesubstrate, and the substrate sensing means may include displacementsensing means which senses whether the projecting heights of therespective lift pins are changed.

The displacement sensing means may sense the displacement of at leastone of the lift pins, or may respectively sense the displacement of allthe lift pins.

An elastic member may be installed between each lift pin and the liftpin support structure. The displacement sensing means may include asensor installed along each line of action, along which the load of thesubstrate compresses the elastic member to decrease the distance betweenthe lift pin and the lift pin support structure, to be actuated by theload of the substrate.

In certain embodiments, the displacement sensing means may also includea light emitting sensor, and a light receiving sensor for receiving asignal from the light emitting sensor. One sensor of the light emittingsensor and the light receiving sensor may be installed on the lift pin,and the other sensor may be located to be opposite the one sensor whendisplacement occurs in the lift pin.

In alternative embodiments, the displacement sensing means may include alight emitting sensor, and a light receiving sensor for receiving asignal from the light emitting sensor. The light emitting sensor and thelight receiving sensor may be located opposite each other, with the liftpin interposed therebetween. A signal transmission hole may be definedthrough the lift pin such that the light receiving sensor may receivethe signal from the light emitting sensor when displacement occurs inthe lift pin.

In alternative embodiments, the displacement sensing means may include areflection plate, a light emitting sensor for outputting a signal to thereflection plate, and a light receiving sensor for receiving the signaloutputted from the light emitting sensor and reflected by the reflectionplate. The reflection plate may be installed on the lift pin. The lightemitting sensor and the light receiving sensor may be installed tooutput the signal to the reflection plate when displacement occurs inthe lift pin, and then receive the reflected signal.

Each lift pin may be divided into an upper pin and a lower pin, and anelastic member may be installed between the upper pin and the lower pin.

The displacement sensing means may include a sensor installed along eachline of action, along which the load of the substrate compresses theelastic member to decrease the distance between the upper pin and thelower pin, to be actuated by the load of the substrate.

In alternative embodiments, the displacement sensing means may alsoinclude a light emitting sensor and a light receiving sensor forreceiving a signal from the light emitting sensor. One sensor of thelight emitting sensor and the light receiving sensor may be installed onthe upper pin of the lift pin, and the other sensor may be located to beopposite the one sensor when displacement occurs in the lift pin.

In alternative embodiments, the displacement sensing means may include alight emitting sensor, and a light receiving sensor for receiving asignal from the light emitting sensor. The light emitting sensor and thelight receiving sensor may be located opposite each other, with theupper pin of the lift pin interposed therebetween, and a signaltransmission hole may be defined through the upper pin of the lift pinsuch that the light receiving sensor may receive the signal from thelight emitting sensor when displacement occurs in the lift pin.

In alternative embodiments, the displacement sensing means may include areflection plate, a light emitting sensor for outputting a signal to thereflection plate, and a light receiving sensor for receiving the signaloutputted from the light emitting sensor and reflected by the reflectionplate. The reflection plate may be installed on the upper pin of thelift pin. The light emitting sensor and the light receiving sensor maybe installed to output the signal to the reflection plate whendisplacement occurs in the lift pin and then receive the reflectedsignal.

The determination means may include control means, and the device canfurther comprise notification means for making known the presence or theabsence of the substrate under the control of the control means.

In a device for determining the presence or the absence of a substrateaccording to embodiments as broadly described herein, whether the loadof a substrate acts on the lift pins is sensed by the substrate sensingmeans and the determination means, and the presence or the absence of asubstrate is determined depending upon the sensing result, wherebyadvantages are provided in that the presence or the absence of asubstrate may be quickly and conveniently determined.

A method is provided for introducing a substrate into a chamber, whereina device for determining the presence or the absence of a substrate,which senses a load and a displacement, may be used, and theintroduction of a substrate into the chamber may be permitted only whenanother substrate is not present in the chamber, so that a substrate maybe prevented from being introduced into the chamber while anothersubstrate is present in the chamber and another substrate in the chambermay be prevented from being broken due to interference with a transferrobot.

A method for introducing a substrate into a chamber as embodied andbroadly described herein may include determining whether a substrate ispresent or absent on a stage, using the device for determining thepresence or absence of a substrate; and transferring a substrate to beprocessed onto the stage when it is determined that no substrate ispresent on the stage.

The method may also include making known the presence of a substratewhen it is determined that the substrate is present on the stage.

In a method for introducing a substrate into a chamber, which uses thedevice for determining the presence or the absence of a substrate asembodied and broadly described herein, since a substrate may beintroduced into the chamber only when it is determined by thedetermination means that no substrate is present in the chamber, it maybe possible to prevent a substrate from being introduced while anothersubstrate is present in the chamber. As a consequence, it may bepossible to prevent another substrate in the chamber from being brokendue to interference with a transfer robot.

A method for inspecting a substrate is provided, wherein a device fordetermining the presence or the absence of a substrate, which senses aload, is used, whether the load of a substrate acts on all lift pins issensed, and, if there is at least one lift pin on which the load of thesubstrate does not act, it is determined that a portion of the substrateis broken or the substrate has been erroneously loaded, whereby thestate of the introduced substrate can be easily detected.

A method for inspecting a substrate using a load sensing type device fordetermining the presence or absence of a substrate as embodied andbroadly described herein may include sensing whether a load of asubstrate acts on all lift pins when the substrate is introduced into achamber; and determining the broken state of the substrate or theerroneously loaded state of the substrate depending upon the result ofsensing whether the load of the introduced substrate acts on all thelift pins.

The method may also include making known the broken state of thesubstrate or the erroneously loaded state of the substrate when it isdetermined that the substrate is broken or has been erroneously loaded.

In a method for inspecting a substrate according to embodiments asbroadly described herein, when sensing whether the load of a substrateacts on the lift pins, all the lift pins may be respectively sensed, andif at least one lift pin does not input a sensing result, it may bedetermined that a portion of the substrate is broken or the substratehas been erroneously loaded and therefore there is at least one lift pinon which the load of the substrate does not act, whereby the(appropriate or inappropriate) state of the introduced substrate may beeasily detected.

A method is provided for inspecting a substrate, wherein a device fordetermining the presence or the absence of a substrate as embodied andbroadly described herein, which senses displacement, may be used,whether displacement occurs in all lift pins may be sensed, and, ifthere is at least one lift pin in which displacement does not occur, itmay be determined that a portion of the substrate is broken or thesubstrate has been erroneously loaded, whereby the state of theintroduced substrate may be easily detected.

A method is provided for inspecting a substrate using a displacementsensing type device for determining the presence or absence of asubstrate as embodied and broadly described herein may include sensingwhether a substrate displaces all lift pins when the substrate isintroduced into a chamber; and determining a broken state of thesubstrate or an erroneously loaded state of the substrate depending uponthe result of sensing whether displacement occurs in all the lift pinsdue to the introduced substrate.

The method may also include making known the broken state of thesubstrate or the erroneously loaded state of the substrate when it isdetermined that the substrate is broken or has been erroneously loaded.

In a method for inspecting a substrate according to embodiments asbroadly described herein, when sensing whether displacement occurs inthe lift pins, all the lift pins may be respectively sensed, and if atleast one lift pin does not input a sensing result, it may be determinedthat a portion of the substrate is broken or that the substrate has beenerroneously loaded, and therefore there is at least one lift pin onwhich the load of the substrate does not act, whereby the (appropriateor inappropriate) state of the introduced substrate may be easilydetected.

A device is provided for determining the opening or the closing of agate valve, in which the state of a gate valve is sensed, and whetherthe gate valve may be opened or closed may be determined depending uponthe sensing result, whereby advantages are provided in that a worker mayquickly and conveniently confirm the opening or the closing of the gatevalve.

A device for determining the opening or closing of a gate valve asembodied and broadly described herein may include gate valve sensingmeans for sensing the opened state or a closed state of a gate valve foropening and closing a gate slit of a chamber; and determination meansfor receiving a sensing result from the gate valve sensing means anddetermining the opening or closing of the gate valve.

The gate valve sensing means may include a light emitting sensor, and alight receiving sensor for receiving a signal outputted from the lightemitting sensor. One sensor of the light emitting sensor and the lightreceiving sensor may be installed on the gate valve, and the othersensor may be located to be opposite the one sensor.

The gate valve sensing means may include a reflection plate, and anoptical sensor module for outputting a signal to the reflection plateand receiving the signal reflected by the reflection plate. One of thereflection plate and the optical sensor module may be installed on thegate valve, and the other may be located to be opposite the first one.

In certain embodiments, one of the gate valve sensing means, which isinstalled on the gate valve, may be placed on the outer side of the gatevalve, and the other of the gate valve sensing means may be installed ona transfer robot for transferring the substrate to introduce anddischarge the substrate into and from the chamber.

In alternative embodiments, one of the gate valve sensing means, whichis installed on the gate valve, may be placed on the outer side of thegate valve, and the other of the gate valve sensing means may beinstalled on a guide which guides the movement of a transfer robot forintroducing and discharging the substrate into and from the chamber.

The gate valve sensing means may include a sensor installed along a lineof action, along which force for closing the gate valve acts on the gatevalve, to be actuated by the force for closing the gate valve.

The determination means may include control means; and the device mayalso include notification means for making known the opening or theclosing of the gate valve under the control of the control means.

In a device for determining the opening or the closing of a gate valveaccording to embodiments as broadly described herein, advantages areprovided in that, since the opening or the closing of the gate valve maybe sensed using the gate valve sensing means, and whether the gate valveis opened or closed may be determined depending upon the sensing resultand then made known, the opening or the closing of the gate valve may bequickly and conveniently confirmed, and the (opened or closed) state ofthe gate valve may be precisely recognized.

A method is provided for introducing a substrate into a chamber, whereina device for determining the opening or the closing of a gate valve asembodied and broadly described herein is used, and a substrate may beintroduced into the chamber only when the gate valve is opened, wherebyit may be possible to prevent a substrate from being introduced whilethe gate valve is closed, so that the substrate and a transfer robot, onwhich the substrate is placed, may be kept from being damaged due tocollision with the gate valve.

A method for introducing a substrate into a chamber as embodied andbroadly described herein may include determining whether a gate valve isopened or closed, using the device for determining the opening orclosing of a gate valve; and transferring a substrate to be processedinto the chamber when it is determined that the gate valve is opened.

The method may also include making known the closing of the gate valvewhen it is determined that the gate valve is closed.

In a method for introducing a substrate into a chamber according toembodiments as broadly described herein, which uses the device fordetermining the opening or the closing of a gate valve, advantages areprovided in that, since a substrate may be introduced only when it isdetermined by the determination means that the gate valve is opened, itmay be possible to prevent a substrate to be processed from beingintroduced into the chamber while the gate valve is closed, so that thesubstrate and a transfer robot, on which the substrate is placed, may bekept from colliding against the gate valve, thereby preventing thesubstrate, the transfer robot and the gate valve from being damaged.

Any reference in this specification to “one embodiment,” “anembodiment,” “example embodiment,” “certain embodiment,” “alternativeembodiment,” etc., means that a particular feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment as broadly described herein. The appearancesof such phrases in various places in the specification are notnecessarily all referring to the same embodiment. Further, when aparticular feature, structure, or characteristic is described inconnection with any embodiment, it is submitted that it is within thepurview of one skilled in the art to effect such feature, structure, orcharacteristic in connection with other ones of the embodiments.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

What is claimed is:
 1. A method for introducing a substrate into achamber, the method comprising: determining whether the substrate ispositioned on a stage provided in the chamber; and thereaftertransferring the substrate onto the stage for processing when it isdetermined that there is no substrate positioned on the stage, whereindetermining whether a substrate is positioned on a stage comprises:sensing whether a load generated by a substrate is imparted on aplurality of lift pins that extend upward from the stage; determiningthat a substrate is positioned on the stage if a load is imparted oneach of the plurality of lift pins; and determining that a substrate isnot positioned on the stage if no load is imparted on each of theplurality of lift pins.
 2. The method of claim 1, further comprisingdetermining a condition of the substrate if it is determined that asubstrate is positioned on the stage, comprising determining that thesubstrate is broken or is misaligned on the stage when a load isimparted on only some of the plurality of lift pins.
 3. The method ofclaim 1, further comprising providing a visual or an audible indicationof which of the plurality of pins are carrying a load, and which of theplurality of pins are not carrying a load.
 4. The method of claim 1,wherein sensing whether a load generated by a substrate is imparted onthe plurality of lift pins comprises measuring a displacement of theplurality of lift pins, or receiving a signal indicating that a sensorhas been depressed.